In an effort to bolster sustainability efforts and cut energy costs, the Harvard College Library system has implemented lighting changes, including installing occupancy sensors and reducing lighting use in campus libraries.

According to an HCL press release, the initiative aims to help the University reach its larger sustainability goals, which include a 30-percent reduction in greenhouse gas emissions by 2016 and the implementation of environmentally friendly temperature settings.

“Once President Faust made [sustainability] a priority, we raised our level of awareness and became much more focused as an institution on working together to create a good conservation effort,” said Beth S. Brainard, HCL director of communications.

Several years ago, HCL operations installed a number of occupancy sensors in parts of Widener Library, but another 130 sensors have been added to offices in Widener, Lamont, and Pusey libraries in recent months.

HCL operations have reduced lighting in other areas of the libraries, according to the press statement. Eighty-two lights have been turned off in the Loker Reading Room, resulting in thousands of dollars in savings, and 68 spotlights were dispensed with in the Phillips and stacks reading rooms, which has saved HCL more than $10,000 in annual maintenance fees.

The latest projects—which were initiated by the HCL sector leaders for the University’s Greenhouse Gas Reduction Program—also include installing energy-efficient compact fluorescent bulbs and turning off half the lights in the tunnel between Widener and Lamont, according to the release.

“We are keenly aware of the need to conserve energy. While the current budget stringencies are bringing more attention to these savings, the energy conservation issues are a part of a larger commitment,” HCL’s head librarian Nancy M. Cline wrote in an e-mail. “We are of course glad to see the lower operating costs, as this allows us to redirect this money to other priorities.”

HCL’s recent energy-saving, cost-cutting initiatives reflect the University’s current budgetary concerns. Last month, the Task Force on University Libraries released a report, suggesting the possibility of closing some of Harvard’s 73 libraries and reevaluating the University’s ambitious collection strategy, in order to address budgetary pressures.

Concerning its most recent changes, HCL operations examined each library first and then implemented successful changes among all buildings to create a largely uniform conservation effort, according to Brainard.

“Each library is different. For example, Houghton Library contains rare books and manuscripts. Because of the nature of the materials it houses, we can’t follow the same sort of heating and cooling systems that we do in our other libraries,” Brainard said. “We try to set things across the board where it makes sense.”

The recent changes are part of HCL’s history of enhancing its sustainability efforts. Since 1997, the spaces and buildings managed by HCL Operations—the HCL floors of 625 Mass. Ave., and Widener, Houghton, Lamont, Pusey, and Tozzer libraries—have made dozens of changes devoted to energy conservation.

Prior efforts have included the adjustment of library air-conditioning systems to reflect operating hours—a change that cost a little less than $5,000, but one that has been estimated to save more than $40,000 in annual energy costs, according to the press release.

—Staff writer Barbara B. DePena can be reached at barbara.b.depena@college.harvard.edu.